|Year : 2019 | Volume
| Issue : 4 | Page : 137-140
Asymptomatic triple vessel coronary artery disease: A treatment dilemma
Senior Consultant in Internal Medicine and Diabetes and Editor in Chief, APIK Journal of Internal Medicine API Karnataka Chapter, Bangalore, Karnataka, India
|Date of Submission||18-Aug-2019|
|Date of Acceptance||21-Aug-2019|
|Date of Web Publication||18-Oct-2019|
Dr. M Premanath
Prem Health Care, 671, Nrupatunga Road, M-Block, Kuvempunagar, Mysore - 570 023, Karnataka
Source of Support: None, Conflict of Interest: None
Coronary artery bypass graft (CABG) is the treatment of choice in patients of diabetes with triple vessel disease (TVD). If the patient has TVD but is asymptomatic, the dilemma is whether to continue with medical management or to opt for revascularization. The patient in this case report was absolutely asymptomatic despite risk factors of diabetes, resistant hypertension, and TVD. Since his left main coronary artery was involved, he underwent CABG to prevent sudden cardiac death.
Keywords: Asymptomatic, coronary artery disease, diabetes, triple-vessel coronary artery disease
|How to cite this article:|
Premanath M. Asymptomatic triple vessel coronary artery disease: A treatment dilemma. APIK J Int Med 2019;7:137-40
| Introduction|| |
Triple-vessel coronary artery disease (CAD) (TVD), that too in a diabetic patient means, invariably coronary artery bypass graft (CABG). If the patient is symptomatic, there is no problem in arriving at a decision. If the patient does not have any symptoms and coronary angiogram reveals TVD, there is a dilemma of what should be done. “Even in patients with left main and severe three-vessel disease, proof is lacking that prophylactic revascularization is of any value if the patients are asymptomatic” is a statement that appeared in a book on cardiology. If the patient is symptomatic to begin with, and becomes asymptomatic after surgery, that is a yardstick to measure the efficacy of the treatment, but what happens in those who are asymptomatic to begin with and remain asymptomatic after the procedure. The following case is one such case where the patient was asymptomatic throughout, which caused a dilemma in his further management.
| Case Report|| |
Mr N, a 66-year-old male, a diabetic of more than 6 years was on oral hypoglycemic drugs and was under tolerably good control. He was also a hypertensive which was resistant to treatment and was taking telmisartan, nebivolol, cilnidipine, moxanidine, chlorthalidone, prazosin, and Aldactone for the control of his blood pressure (BP), but still, his BP was 150/80 mmHg. He was not a smoker, not used to alcohol, and a vegetarian. He was an avid walker and used to walk 5–6 km daily and did not have any effort angina or dyspnea. Other investigations done routinely revealed hemoglobin A1C of 8%, serum creatinine – 1.4 mg/dl, fetal bovine serum – 129 mg%, microalbuminuria – 42 mcg/mg of creatinine and lipid profile – cholesterol – 224 mg%, triglycerides – 339 mg%, high-density lipoprotein – 44 mg%, and low-density lipoprotein – 139 mg%. His electrocardiography (ECG) was done as a routine procedure and showed signs of left ventricular (LV) strain and inferior and lateral wall ischemia [Figure 1]. He was subjected to treadmill testing (TMT), and the subsequent ECG's showed increased ST- and T-changes in the same leads as the rest ECG and even the ECG 3 min after recovery showed similar changes; another interesting finding was the elevation of the ST-segment in lead aVR during the exercise [Figure 2], [Figure 3], [Figure 4], [Figure 5]. He did not have any effort angina during TMT. His ECHO showed good LV function with an ejection fraction of 64%. Coronary angiogram was done. It showed a calcific LM coronary artery with distal 50% disease; left anterior descending artery showed a type III calcific vessel with 90% osteoproximal lesion with diagonal branches being normal; circumflex artery was dominant, calcific, and showed 80% proximal lesion; left posterior descending artery (LPDA) showed 60% lesion with obtuse marginal arteries being normal; and right coronary artery was non dominant, calcific, and showed 50% proximal lesion. The impression was TVD [Figure 6]. Since the patient was asymptomatic, but had a positive stress test and a TVD on angiogram, he was subjected to a myocardial perfusion scan which showed a mild reversible perfusion defect involving the septum; all other segments of myocardium showing normal perfusion at stress and rest and all the segments showed normal wall movements in gated single-photon emission computed tomography images [Figure 7]. The impression was a normal perfusion scan for all practical purposes. The patient continued to be asymptomatic throughout all the procedures and after. He was explained that he can continue medical management or would have to undergo a CABG and would not find any difference as he was asymptomatic. He left the decision to the treating physician.
| Discussion|| |
Normally, TVD that too in a case of diabetes, the treatment is a CABG and there is no ambiguity in this. Most of them will be symptomatic with angina pectoris or exertional dyspnea, and treatment with CABG would relieve their symptoms. Patients will be happy as the treatment would improve their activities, and the doctor would be happy for obvious reasons. Taking this case as an example, this patient was absolutely asymptomatic despite walking 5–6 km/day, and a chance ECG revealed the findings of myocardial ischemia which resulted in a host of investigations. The screening guidelines of the American Diabetes Association (ADA) way back in 1992 reported that asymptomatic diabetic patients with more risk factors were more likely to have significant CAD than a single risk factor. This assumption was disproved by a study in 2006, which showed that the occurrence of myocardial perfusion defects and CAD was similar whether the patient had one or more risk factors. The present patient had three risk factors and TVD. In that, contest selection of treatment had to be noncontroversial and should have been revascularization. However, this patient was absolutely asymptomatic. The latest standard of care in diabetes by the ADA  is very clear on this patient. It stated “In asymptomatic patients, routine screening for coronary artery disease is not recommended as it does not improve the out comes as long as atherosclerotic cardiovascular risk factors are treated. The screening of asymptomatic diabetic patients with high ASCVD risk is not recommended, in part because these high risk patients would already been receiving intensive medical therapy which would provide similar benefit as invasive revascularization.” This patient was getting optimum therapy for his diabetes and his BP which was resistant in nature and was in tolerably good control with a host of antihypertensive drugs. A study in 1984 tried to detect significant CAD in asymptomatic men through clinical and exercise test variables compared to angiographic findings and came to the conclusion that none of the clinical or ECG at rest variables could detect CAD. They concluded that a risk factor along with individual exercise ECG variables may have a high predictive value for significant CAD.
Then, why did this patient was asymptomatic despite high-risk factors and TVD? The plausible answer would be that he had a very slow coronary artery occlusion which had paved the way for opening of maximum collaterals which resulted in optimum circulation. The only troublesome feature in this patient was the involvement of LM coronary artery. A study done in 1982 showed that asymptomatic patients with single- or double-vessel disease had excellent prognosis, whereas those with TVD even with good exercise tolerance had 4% annual mortality. Theoretically demonstration of myocardial ischemia by TMT or ambulatory ECG would support revascularization based on the anatomy and presence of ischemia in the absence of symptoms; such treatment has not shown to be efficacious in clinical trials.
Hence, what was the treatment recommended in this patient? The patient would have been left alone if his LM coronary artery was not involved. To prevent sudden cardiac death, CABG was recommended.
Foot Note: The patient underwent minimally invasive CABG. He was asymptomatic prior to the surgery and continues to be asymptomatic after the surgery.
| Conclusion|| |
This is the story of an asymptomatic diabetic, hypertensive patient who showed TVD on angio and almost normal perfusion scan. Whether to continue his medical treatment or whether to opt for revascularization was the dilemma. The involvement of LM tilted the treatment for revascularization. If LM was not involved, medical management would have been sufficient. Revascularization makes no difference in asymptomatic patients with TVD on optimal medical management except the exception cited above.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5], [Figure 6], [Figure 7]